1. Field of the Invention
The invention relates to a permanent magnet rotor of a motor.
2. Description of the Related Art
As shown in FIG. 1, grooves 18 are usually disposed in an iron core 1 to hold tegular magnets for a conventional permanent magnet rotor and a narrow edge 21 is disposed at the two ends of each groove 18 and at the rotor periphery. Although magnetic short circuits are reduced by magnetic circuit saturation, they cannot be completely eliminated. For further reasons that the narrower edge is more preferred to avoid the magnetic short circuits, rotor laminations are difficult to be made, the narrow edge 21 is likely to deform to make it difficult for the tegular magnet to be inserted in the groove, and moreover the tegular magnet needs to be finely finished before being inserted in the groove; if the groove is too small, the tegular magnet cannot be inserted; if the groove is too big, a gap would occur, leading to the increased magnetic pressure drop, therefore the manufacturability is poor, the assembly speed is slow, product quality is hardly to be guaranteed, and the electromagnetic performance is unsatisfactory.